Team: Aerosols and Radiation

Methodologies and products related to aerosol particles in the atmosphere and solar radiation are developed, evaluated, and demonstrated for use when dealing with issues such as air quality, health, renewable energies and climate. The focus is on exploiting the synergies from joint consideration of satellite measurements and models, and on monitoring and taking into account atmospheric soot and mineral particles.

Two new approaches have been developed for the satellite-based remote sensing of aerosols. SYNAER uses the complementary information coming from two sensors on one platform to determine the composition of aerosols made up of secondary aerosols, marine salts, soot and mineral particles. With the help of a bi-temporal dust index it is possible to detect sand storms also over bright deserts with data collected by the geostationary MSG-SEVIRI sensor.

Long-duration time series and near-real-time data obtained with these new approaches are being integrated into atmosphere models using innovative methods of data assimilation, which makes it possible to monitor and forecast aerosol distribution for large areas. A major component of data assimilation is detailed analysis of the information content of the satellite data and the subsequent derivation of a mathematically consistent formulation of covariances for measurement and model errors.

This same aerosol data combined with satellite measurements of cloud cover, water vapor columns, ozone content and snow cover are the basis for precisely characterizing the solar radiation available at ground level for photovoltaic and solar thermal facilities. In addition to the historical mapping of solar radiation, new efforts aim at predicting this radiation for subsequent hours and days, information which is required for solar facility monitoring, power plant control and network integration. Toward this end, methods are being developed for obtaining improved forecast data for aerosols (for example by optimizing the definition of dust mobilization processes in aerosol models) and cloud cover (by deriving short-range forecasts of cloud movement based on data from geostationary satellites).

Particulate Matter in the Air of Riyad

Besides applications relevant for renewable energies, the aerosol data is also used to determine when the limits set to assure air quality have been exceeded, to analyze the relationship between respiratory illnesses and particulate matter in the air, as well as to investigate the interactions between aerosols, clouds and precipitation over large areas. Concentrations of particulate matter at ground level are derived from satellite-based determinations of aerosol content and composition combined with model data on the vertical layering of aerosols. The interaction of aerosol particles with clouds and precipitation are studied using time series composed of several years’ worth of satellite measurement of these variables. Other applications use aerosol and cloud information for the atmospheric correction of satellite observations of the land surface and to obtain quantitative values for photosynthetically relevant radiation for use in biomass and carbon cycle modeling.